I sometimes upvote my own comments so that they are seen, but I don't do it all the time. It's very unlikely that every user would decide to only upvote their own posts and comments. A lot of people are here to network with other people, as that may be much more valuable then just getting a few cents by upvoting your own stuff.
In any case, I'm happy to be here. Wish I'd started using Steemit sooner.
The problem isn't with getting a few extra cents here and there. The larger accounts are able to allocate 10's and 100's of dollars per upvote, and if they wanted to they could direct that all towards their own comments and posts, which in the current system would actually give them the most "bang for their buck". Which is exactly why I think things need to be tweaked...
We want a system that incentivizes helping others while also helping yourself.
That's why I think point 3) is the way to go: Increase the curation rewards!